The present invention relates to positioning a graphics cursor on a computer display and to a positioning device that permits both absolute and relative positioning.
The prior art contains many devices for positioning a graphics cursor within a graphics user interface (GUI) Examples of known input or positioning devices include touchpads, touch screens, track balls, computer tablets and computer mouse products. These devices utilize either absolute or relative positioning schemes to achieve placement of a cursor at a desired location.
Absolute positioning schemes are commonly implemented in devices such as graphic tablets and touch screens. In absolute positioning, there is a one to one correspondence between a point on the positioning device and a point on the computer screen. Thus, designation of a point on the positioning device results in a predefined response at the corresponding position on the computer screen. Disadvantages of absolute positioning include that the devices tend to be relatively large to maximize the number of selectable points on the input device, the devices tend to lack precision (i.e., fine positioning cannot be achieved) and the devices are often prone to alignment problems in which it is difficult to have specific positions on the input device repeatedly translate to the same point on the computer screen. Relative positioning schemes are commonly utilized in devices such as track balls, mice and touchpads, etc. In relative positioning, a graphics cursor is positioned by moving an input device relative to its current position. Relative positioning schemes generally strike a compromise between the effective handling of large graphics cursor movements and fine positioning. The result of this compromise is often a positioning device that achieves neither desired levels of large graphics cursor movement or fine positioning.
A related positioning scheme is acceleration-based relative positioning. In this scheme, the rate at which the input device is accelerated corresponds to the rate at which the graphics cursor is moved. While acceleration-based techniques facilitate both fine positioning and large graphics cursor movements, their design and implementation are complicated. The use of acceleration based devices can also be frustrating not only to new users but also to experienced users that are used to a device with a slightly different acceleration sensitivity.
U.S. Pat. No. 5,327,161, issued Jul. 5, 1994, to James Logan and Blair Evans is representative of prior art positioning devices. While prior art positioning devices have contributed to the advancement of computer-user interfaces, there is room for improvement. For example, at times a user may desire absolute positioning to immediately move to a desired location on a screen. At other times, a user may desire relative positioning for efficient placement of a graphics cursor relative to its previous position, e.g., in positioning a graphics cursor amongst text characters.
A need thus exists for a positioning device that provides both absolute positioning, e.g., for large graphics cursor movements, and relative positioning, e.g., for fine placement of a graphics cursor.
Accordingly, it is an object of the present invention to provide a method of achieving both absolute and relative positioning in a computer (or other electronic device) input device.
It is another object of the present invention to provide an input device that is capable of achieving both absolute and relative positioning of a graphics cursor or the like.
It is also an object of the present invention to provide a computer or other electronic device that incorporates such an input device.
These and related objects of the present invention are achieved by use of the apparatus and method for achieving both absolute and relative positioning of a graphics cursor as described herein.
In one embodiment, the present invention includes a method of positioning a graphics cursor that includes the steps of receiving a touched location indicating signal from a touchpad; determining from a touched location indicating signal whether to invoke an absolute positioning mode of operation or a relative positioning mode of operation; and generating, in said absolute positioning mode of operation, a signal that facilitates formation of a graphics cursor on a display at a location that corresponds to an indicated touched location. Other method steps include detecting continually touching movement on a touchpad and generating a signal that facilitates movement of a graphics cursor from a previous position in a manner analogous to movement of detected continually touching movement relative to a reference location.
In another embodiment, the present invention includes an electronic apparatus that includes a touchpad; a display; and processing logic coupled between said touchpad and said display that processes touched location signals from said touchpad in such a manner as to provide absolute or relative positioning of a graphics cursor for said display.
The attainment of the foregoing and related advantages and features of the invention should be more readily apparent to those skilled in the art, after review of the following more detailed description of the invention taken together with the drawings.